/*
 * Copyright (C) 2010-2025 Structr GmbH
 *
 * This file is part of Structr <http://structr.org>.
 *
 * Structr is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Structr is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Structr.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.structr.csv;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.QuoteMode;
import org.structr.docs.Example;
import org.structr.docs.Parameter;
import org.structr.docs.Signature;
import org.structr.docs.Usage;
import org.structr.schema.action.ActionContext;

import java.io.StringReader;
import java.util.List;

public class GetCsvHeadersFunction extends CsvFunction {

	@Override
	public String getName() {
		return "getCsvHeaders";
	}

	@Override
	public List<Signature> getSignatures() {
		return Signature.forAllScriptingLanguages("source [, delimiterChar = ';' [, quoteChar = '\"' [, recordSeparator = '\\n' ]]]");
	}

	@Override
	public Object apply(final ActionContext ctx, final Object caller, final Object[] sources) {

		try {

			assertArrayHasMinLengthAndMaxLengthAndAllElementsNotNull(sources, 1, 4);

			try {

				final String source = sources[0].toString();
				String delimiter = ";";
				String quoteChar = "\"";
				String recordSeparator = "\n";

				switch (sources.length) {

					case 4:
						recordSeparator = (String) sources[3];
					case 3:
						quoteChar = (String) sources[2];
					case 2:
						delimiter = (String) sources[1];
						break;
				}

				CSVFormat format = CSVFormat.newFormat(delimiter.charAt(0)).withHeader();
				if (quoteChar.length() > 0) {
					format = format.withQuote(quoteChar.charAt(0));
				} else {
					format = format.withQuote(null);
				}

				format = format.withRecordSeparator(recordSeparator);
				format = format.withIgnoreEmptyLines(true);
				format = format.withIgnoreSurroundingSpaces(true);
				format = format.withQuoteMode(QuoteMode.ALL);
				format = format.withAllowMissingColumnNames(true);

				try (final CSVParser parser = new CSVParser(new StringReader(source), format)) {

					return parser.getHeaderMap().keySet();
				}

			} catch (Throwable t) {

				logException(t, "{}(): Encountered exception '{}' for input: {}", new Object[]{getName(), t.getMessage(), getParametersAsString(sources)});
			}

			return "";

		} catch (IllegalArgumentException e) {

			logParameterError(caller, sources, e.getMessage(), ctx.isJavaScriptContext());
			return usage(ctx.isJavaScriptContext());
		}
	}

	@Override
	public List<Usage> getUsages() {
		return List.of(
				Usage.structrScript("Usage: ${getCsvHeaders(source[, delimiterChar [, quoteChar[, recordSeparator]]])}. Example: ${getCsvHeaders('COL1;COL2;COL3\none;two;three')}"),
				Usage.javaScript("Usage: ${{Structr.getCsvHeaders(source[, delimiterChar[, quoteChar[, recordSeparator]]])}}. Example: ${{Structr.getCsvHeaders('COL1;COL2;COL3\none;two;three')}}")
		);
	}

	@Override
	public String getShortDescription() {
		return "Parses the given CSV string and returns a list of column headers.";
	}

	@Override
	public String getLongDescription() {
		return "";
	}


	@Override
	public List<Example> getExamples() {
		return List.of(
				Example.structrScript("${getCsvHeaders('COL1;COL2;COL3\\none;two;three')}"),
				Example.javaScript("${{ $.getCsvHeaders('COL1;COL2;COL3\\none;two;three') }}")
		);
	}

	@Override
	public List<String> getNotes() {
		return List.of(
				"An API Key has to be configured in structr.conf.",
				"See the documentation on the Translation module for more info."
		);
	}


	@Override
	public List<Parameter> getParameters() {

		return List.of(
				Parameter.mandatory("source", "CSV string"),
				Parameter.optional("delimiter", "CSV field delimiter, default: ';'"),
				Parameter.optional("quoteChar", "CSV field quotechar, default: '\"'"),
				Parameter.optional("recordSeparator", "CSV record separator, default: '\\n'")
		);
	}
}
